Magnifying and light concentrating device for telephone dials



MILLER 2,509,833

T. MAGNIFYING AND LIGHT CONCEN TING DEVICE FOR TELEPH DI Filed Jan. 16, 47

May 30, 1950 INVENTOR. TOE/A5 MIL L E12 ATTOE/WEXS,

l atented May 30, 1950 U TED STATES PATENT OFFICE MAGNIFYING AND LIGHT CONCENTRATING DEVICE FOR TELEPHONE DIALS Claims. 1

This invention relates to a device for increasing the legibility of numbers, letters and the like and particularly to a device for such purpose which may be attached conveniently to telephone dials and the like.

One of the principal objects of the present invention is to provide a device which both magnifies and concentrates light on indicia placed therebeneath.

A more specific object is to provide a device for magnifying and concentrating light on indicia juxtaposed on or indented in one surface thereof.

Another specific object is to provide an annulus of transparent plastic material arranged to magnify and concentrate light from any direction on indicia indented in the bottom surface thereof, and of which the indented indicia are filled with luminous material so as to be readily visible in magnified condition in the dark.

Another object is to provide a device of the character described and which is easily cleaned.

Other objects and advantages will be apparent from the following description wherein reference is made to the drawings, in which:

Fig. 1 is a perspective view of an embodiment of the device of the present invention;

Fig. 2 is an enlarged fragmentary cross sectional view of the device, taken on line 2-2 of Fig. 1, and showing the device installed on a telephone dial;

Fig. 3 is a plan view of the device installed on a telephone dial; and

Fig. 4 is a fragmentary sectional view, similar to Fig. 2, showing a modified form of the device. Referring to the drawings, the invention is shown as applied to the dial of the usual dial type telephone. As there illustrated the telephone dial includes a base plate I, on the upper surface of which are the usual dial numbers and groups of letters, as illustrated, and an oscillating disc 2 with the usual annular row of finger holes 3 arranged one above each number and its associated group of letters when the disc is in idle position.

protuberances 6, arranged so that each protuberance underlies each hole 3.

The protuberances 6 are preferably spherical segments of spheres of small radius so as to extend abruptly above the upper surface of the annulus 5. For example, they may be hemispheres of diameter slightly greater than the diameter of the associated holes 3.

The exact shape and size of the protuberances may be varied, depending on the light transmitting qualities of the material of which they are composed.

The above proportions are suitable for transparent synthetic plastics such as acrylic resins and cellulose acetate.

The protuberances 6 and ring 5 preferably are formed integral with each other by molding in highly polished chrome plated dies.

When the annulus is installed, its undersurface may rest directly on the upper surface of the plate I so as to be juxtaposed on the numbers and letters thereof. In such position, the protuberances 6 not only magnify the letters and numbers on the plate I but also bend light rays which strike them from any direction and redirect the rays so as to concentrate the light on the letters and numbers.

However, since telephones are frequently located in very dark places, indicia 1 corresponding to the numbers and letters on the plate I may be molded or inscribed in the bottom of the annulus 5 and filled with black or dark paint or substance and the entire bottom of the annulus then coated with white or luminous paint or opaque substance. If desired, of course, this arrangement may be reversed, the indicia being filled with white or luminous substance and the entire bottom being coated ,with black paint or dark opaque substance. Again the molded or inscribed indicia and the opaque coating may be omitted.

The annulus 5 is provided with an integral peripheral flange 8 adapted to fit around the peripheral wall of the plate I, a :nitable notch So being provided in the flange 8 to accommodate the stop 4 with substantial clearance circumferentially of the plate. In order to render the annulus 5 readily installable, it preferably is made in two semi-annular sections, 5a and 5b. The section 5a is provided with hooks 9 at its ends, the hooks having cam shoulders Ill. The section 5b is provided with integral lugs II which, when the sections are forced together, engage the cam surfaces III and spread the hooks 8 which interlock with the lugs .ll after the lugs pass beyond the cam surfaces III. The hooks 9 and lugs ll preferably extend from the top surface of the annulus I to the bottom of the flange 8, and the resiliency of the material of which the annulus,

hooks and lugs is formed is sufficient to clamp the sections a and 5b tightly about the plate I and frictionally prevent the annulus 5 from rotation or axial movement relative to the plate I.

With the device installed, due to the light transmittting and refracting characteristics of the synthetic plastic and the highly raised and short radius surface of the individual protuberances, the light is concentrated on the indicia on the plate I, or on the inscribed indicia if such are used, regardless of the direction of the light rays striking the protuberances. Furthermore, each protuberance, since it extends well above the level of the annulus, can receive light rays from a large number of directions, even from opposite directions, concurrently. Likewise, the magnification of the indicia is effective and clear when viewed from substantially any angle from which the indicia normally could be viewed through the openings 3.

In Fig. 4 is illustrated a modification of the invention in which the annulus I2 is used. The annulus I2 is the same as the annulus 5 except that no indicia are inscribed or molded in the bottom where it overlies the indicia customarily on the dial base plate I, and the undersurface may, if desired, be left unpainted or uncoated. If luminosity is desired, indicia may be painted on the underside of the annulus with luminous paint and a coat of dark opaque material applied over the entire undersurface of the annulus, or the indicia may be painted on with dark paint and the undersurface of the annulus coated with luminous paint.

Also, the annulus I2 is covered with a protective cap I3 of transparent material which preferably is sealed to the annulus at the joints so as to exclude dust and foreign substances. The cap 13 has a fiat upper surface which is easily cleaned.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

l. A magnifying and light concentrating device for association with a telephone dial, comprising an annulus of transparent synthetic plastic material, said annulus having a flat under surface, and means for securing said annulus to the telephone dial with the under surface of said annulus in contact with the indicia bearing base plate of said telephone dial, the upper surface portions of said annulus in radial alignment with each indicia group of said telephone dial base plate being formed into convex curved retracting surfaces, each of which has its principal focal point substantially in the plane of the lower surface of said annulus.

2. A device as defined in claim 1, wherein said retracting upper surface portions are spherical segments.

till

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,466,286 Hearn Aug. 28, 1923 1,484,742 Sherwin Feb. 26, 1924 1,553,356 I Garrett Sept. 15, 1925 1,723,297 Norton Aug. 6, 1929 1,823,958 Sorrells Sept. 22, 1931 1,860,606 Carroll May 31, 1932 2,061,097 Fordyce Nov. 17, 1936 2,147,944 Gerrells Feb. 21, 1939 2,195,672 Gerrells Apr. 2, 1940 2,198,935 Dormont Apr. 30, 1940 

